S-8357B50MA-NJJT2G Seiko Instruments, S-8357B50MA-NJJT2G Datasheet - Page 28
S-8357B50MA-NJJT2G
Manufacturer Part Number
S-8357B50MA-NJJT2G
Description
IC REG CTRL PWM 5.0V 6-SNB
Manufacturer
Seiko Instruments
Type
Step-Up (Boost)r
Datasheet
1.S-8355K18MC-NADT2G.pdf
(77 pages)
Specifications of S-8357B50MA-NJJT2G
Internal Switch(s)
No
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
5V
Current - Output
100mA
Frequency - Switching
100kHz
Voltage - Input
0.9 ~ 10 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
6-SNB
Power - Output
150mW
Output Voltage
5 V
Input Voltage
10 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
28
STEP-UP, SUPER-SMALL PACKAGE, 600 kHz, PWM CONTROL or PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER
S-8355/56/57/58 Series
Integration of the equation (6) is as follows :
During t
the energy of the capacitor (C
after M1 is turned ON (t
the voltage of C
when the current flowing through into V
Next, the ripple voltage is determined as follows.
I
When M1 is turned OFF (t
When substituting equation (10) for equation (9) :
Electric charge
When substituting equation (12) for equation (9) :
A rise in voltage (V
When taking into consideration I
When substituting equation (11) for equation (15) :
Therefore to reduce the ripple voltage, it is important that the capacitor connected to the output pin has a large capacity
and a small R
OUT
∴
I
I
⎛
⎜
⎜
⎝
t
Δ
Δ
V
V
V
L
vs. t
OUT
1
V
Q
Q
P
P
P
=
t
=
−
−
−
1
OUT
1
1
P
P
P
I
ON
t
=
PK
=
1
=
OFF
=
=
=
=
I (
(time) from when M1 is turned OFF (after t
I
, the energy is stored in L and is not transmitted to V
I
PK
+
∫
PK
−
PK
Δ
I (
Δ
L
C
C
1 t
0
V
−
PK
⎛
⎜
⎝
Q
Q
−
I
−
L
L
D
−
ESR
V
⎛
⎜
⎜
⎝
L
1
1
I 2
⎛
⎜
⎝
dt
−
I
I
OUT
−
1
2
Δ
L
OUT
OUT
I
=
PK
=
V
PK
I
.
V
Q
(
OUT
rises rapidly. V
=
OUT
I
PK
C
C
IN
1
1
P
1
+
)
I
⎞
• ⎟ ⎟
⎠
L
L
PK
−
•
⎞
⎟
⎟
⎠
which is charged in C
L
)
P
V
−
•
2
•
+
⎛
⎜
⎜
⎝
) due to
=
t
D
I
•
⎛
⎜
⎝
OFF
OUT
⎛
⎜
⎝
L
V
•
V
ON
I
−
t
I
∫
OUT
I
PK
D
PK
OFF
t
PK
C
OFF
OFF
V
). When M1 is turned OFF, the energy stored in L is transmitted through the diode to C
0
1 t
−
)
L
IN
dt
+
•
+
2
2
V
+
), I
I
t
I
⎞
• ⎟
⎠
OUT
+
IN
1
OUT
L
L
−
V
Δ
) is consumed. As a result, the pin voltage of C
=
L
⎛
⎜
⎝
D
⎞
• ⎟
⎠
V
Q
t
OUT
I
= 0 (when the energy of the inductor is completely transmitted). Based on equation (7) :
OUT
PK
I
−
OUT
⎞
• ⎟
⎠
⎞
• ⎟
⎠
PK
1
t
1
V
:
+
1 t
t
to be consumed during t
IN
+
2
is a time function, and therefore indicates the maximum value (ripple voltage (V
2
1
I
+
OUT
I
+
⎞
⎟
⎟
⎠
OUT
L
OUT
V
⎛
⎜
⎝
D
I
PK
⎞
• ⎟
⎠
L
•
−
and load current (I
during t
t
+
R
V
1
2
I
IN
ESR
OUT
Seiko Instruments Inc.
•
∫
⎞
• ⎟
⎠
1
1 t
0
:
ON
R
tdt
ESR
) to when V
=
I
−
PK
I
OUT
1
•
OUT
and the Equivalent Series Resistance (R
C
OUT
t
1
L
•
) match.
−
t
. When receiving the output current (I
OUT
1
V
OUT
reaches the maximum level :
+
L
V
D
−
L
V
is reduced, and goes to the lowest level
IN
•
2
1
t
1
2
ESR
OUT
) of C
Rev.7.0
) from V
L
:
L
, and
OUT
(10)
(11)
(12)
(13)
(14)
(15)
(16)
P
(7)
(8)
(9)
_00
−
P
,
) )